Technical Field
The present invention is related to an oxygen saturation technique, and particularly to an oxygen saturation measuring device and method.
Related Art
Oxygen concentration, also named as oxygen saturation, is crucial to human body health, some oxygen saturation measuring techniques are accordingly set forth, whereby achieving the purpose of disease prevention and monitoring.
An oximeter is a medical instrument measuring an oxygen containing amount in hemoglobin in human body. Dislike the measurement of blood collection/sampling, the oximeter does the measuring job based on non-invaded optical modulation mechanism, in which two optical beams having respective wavelengths which may be absorbed by oxyhemoglobin and deoxyhemoglobin in human body are provided for measurement. After the two optical beams transmit on a selected skin area with blood vessel below, a concentration of the oxyhemoglobin and deoxyhemoglobin may be measured respectively according to a variation from the incident light to the transmitted light.
The subject portion of the human body for the measurement may be a finger, a lobe, and a thigh. The transmitted light may be used as a basis for determining the oxygen saturation is because the intensity of incident light may be affected by the concentration of oxyhemoglobin and deoxyhemoglobin. Thereafter, the photoelectric conversion technique is used to acquire respective electric type signals of the oxyhemoglobin and deoxyhemoglobin. By means of computation conducted in the microprocessor, oxygen saturation equations defined previously in the microprocessor may calculate the oxygen saturation value.
Generally, the red light and infrared light are taken as the two light sources for measurement, and their wavelengths are 660 nm and 940 nm. In addition, the prior such device only uses a point light source for a single point of the skin for measurement. However, if the testee has a weak distal blood circulation, the obtained oxygen saturation information cannot exactly reflect the test's general oxygen saturation, and may not acquire the oxygen saturation information of other portions of the skin at one time. To obtain the oxygen saturation information for a specific area of the skin, the oximeter has to be used several times. However, one time of such measurement may only be conducted for a single point of the skin.
Typically, such prior device uses the transmitted light as the basis for determination of the output light intensity of the red light and infrared light. However, the transmitted light based measurement of oxygen saturation is apt to be affected by the lower blood amount, different skin colors, and irregular heart pulse. Therefore, the accuracy of such measurement needs to be promoted and verified. There has been a technique of determining the oxygen saturation by receiving a reflected red light and infrared light as the output lights, but the measured scope is still limited to a single point.
In view of the above, the prior oximeter still has to be improved to further satisfy the use of oxygen saturation measurement, and the present invention discloses accordingly an image oxygen saturation measurement device and method, whereby enhancing convenience and accuracy of the currently available such device.